The present invention relates to a pad arrangement and pad structure of a semiconductor device, and more particularly to a semiconductor pellet having electric pads arranged in a plurality of parallel lines on the periphery thereof.
In the semiconductor device, the electric pads are supplied in order to provide voltage and input-output a signal for functioning as a circuit. The electric pad is electrically connected to a substrate for a ball grid array (BGA) and a lead frame as an input/output terminal of a semiconductor integrated circuit. In order to shorten the distance for wire bonding connection, the electric pads are generally formed on the periphery of the semiconductor pellet. The wire bonding connection is performed using a metal ball made from for example gold pressed to the electric pad. Connecting points are then bridged through the empty space by a thin wire which is then pressed to the lead frame. Thus, the electric pads require a much wider area than the area of the portion in which the metal ball is pressed.
On the other hand, as a result of integrated circuits becoming microscopic, the number of electric pads provided in the semiconductor pellet increases. Because of this, it becomes difficult to arrange the electric pads in a line on the periphery of the semiconductor pellet. To overcome this, the electric pads are arranged in double lines for a semiconductor pellet where many electric pads are provided.
The conventional technology in which the electric pads are arranged in double lines is disclosed in Japanese laid-open-patent No. HEI 2-119233 and HEI 2-186650.
However, in a semiconductor pellet having electric pads with the above described double line structure, when the connecting points between the electric pads and the lead frame or the substrate have been connected electrically by wire bonding, there can be a problem where the distance between the thin metal wires of the wire bonding causes short-circuits because of the semiconductor pellet's position, deviation, and so forth.